I did this before giving up and buying a BOSCH rebuilt IP, I used a magnet to remove the old DV's, they're two pieces that are machined as pairs so don't mice them up ! .
I had to search a lot of old IP's to find un rusted DV's, eventually I bought new DV's from the M-B Classic Center, they were not terribly expen$ive, too late I discovered you're supposed to replace the little springs too....
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Yes, the new DV's helped a lot but I think that IP was toast in spite of coming from a low mileage 300SD that had clear clean fuel in it .
I spent some time tweaking the ALAD's adjustment to get decent power and little smoke, this pump is apparently doing O.K. in another member here's car ~ I gave it to him and he's well pleased with it .
Many have said that new DV's & springs helps smooth up both hot idle and overall running so might as well give it a try .